STAFFORD - A 42-year-old case involving two missing youths from a state school led FBI agents to search a remote part of the Edwin B. Forsythe National Wildlife Refuge Tuesday.

FBI officials would not comment on what they termed an "investigative activity" off Mayetta Landing Road near the Barnegat Bay that involved several SUVs, a blocked off road and a number of agents and investigators.

David Williams, 12, of Newark went missing in April of 1975 from the New Lisbon State School.(Photo: Photo provided)

However, the investigation apparently centered around two boys who went missing from the New Lisbon State School in Burlington County four decades ago, according to reports from News 12 New Jersey and WPVI-TV in Philadelphia.

The school is about 25 miles from Stafford, an almost direct drive along Route 72 to Mayetta Landing Road.

The FBI added the two boys to its webpage for kidnapped and missing persons this October. The bureau added photos of the two at the time of their disappearance and also provided age-enhanced images to show what they might look like today. There was no indication if Williams or Anderson were alive or dead.

This photo is age progressed to show how the FBI believes Williams would look at the age of 48 years old.(Photo: Photo provided)

The FBI missing persons website stated that "Both boys lived at the 1,898-acre (New Lisbon) center located off Route 72 in the New Jersey Pinelands. They had diagnosed developmental disabilities and were unable to care for themselves without supervision. The boys, who were roommates, were last seen at approximately 4:15 p.m., walking towards their residence from a nearby ball field where they had been playing with staff members."

A Stafford police car parked along the side of Main St. in Stafford the afternoon of Nov. 28.(Photo: Katie Park)

The FBI asked anyone with information to call its Atlantic City office at 609-677-6400 or to contact a local FBI office or a United States embassy or consulate.

Stafford police directed inquiries to the FBI.

The FBI and other law enforcement partners arrived at the refuge Tuesday, said Doreen Holder, a spokeswoman for the FBI. Holder declined to offer more detail on what kind of "investigative activity" law enforcement conducted at the park Tuesday or which agencies the FBI was working with.

Steven Anderson, 17, of Westville went missing from the New Lisbon State School in 1975.(Photo: Photo provided)

A member of the Ocean County Prosecutor's Office was at the scene, the office confirmed.

Parts of Route 9 are populated with residential and commercial development. But less than a mile east of Route 9, the area around the Forsythe wildlife refuge, development is sparse.

The refuge is a federal wildlife area that encompasses 42,000 coastal acres in Ocean and Atlantic counties.